Field of the Invention
The herpes viruses include the herpes simplex viruses, comprising two closely related variants designated types 1 (HSV-1) and 2 (HSV-2). These types cross react strongly but can be distinguished by neutralization titrations. HSV-1 and HSV-2 are responsible for a variety of human diseases, such as skin infections, genital herpes, viral encephalitis and the like.
The herpes simplex virus is a double stranded DNA virus having a genome of about 150 to 160 kbp packaged within an icosahedral nucleocapsid enveloped in a membrane. The membrane includes a number of virus-specific glycoproteins, the most abundant of which are gB, gC, gD and gE, where gB and gD are cross-reactive between types 1 and 2.
It is a matter of great medical and scientific interest to provide safe and effective vaccines for humans against both HSV-1 and HSV-2 and, where infection has occurred, therapies for treatment of the disease.
One promising approach has been the use of isolated glycoproteins, which have been shown to provide projection when injected into mice subsequently challenged with live virus. However, the availability of the Herpes Simplex glycoproteins has heretofore been primarily dependent upon the growth of the virus and the isolation of the membranous proteins. The problems of commercial production of the glycoproteins associated with the handling of a dangerous pathogen, the maintenance of the virus in cell culture, the isolation of the glycoproteins free of the viral genome or portions thereof, have substantially precluded the use of the glycoproteins as vaccines. It would therefore be desirable to provide vaccines employing glycoproteins produced by methods other than by growth of the virus and isolation of the membranes proteins.
There is also substantial interest in developing methods for prophylactically treating herpes infections. Since viral infections are normally resistant to treatment with antibiotics, other techniques which do not have significant side effects are of great interest.